CVE-2025-38682

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

i2c: core: Fix double-free of fwnode in i2c_unregister_device()

Before commit df6d7277e552 ("i2c: core: Do not dereference fwnode in struct

device"), i2c_unregister_device() only called fwnode_handle_put() on

of_node-s in the form of calling of_node_put(client->dev.of_node).

But after this commit the i2c_client's fwnode now unconditionally gets

fwnode_handle_put() on it.

When the i2c_client has no primary (ACPI / OF) fwnode but it does have

a software fwnode, the software-node will be the primary node and

fwnode_handle_put() will put() it.

But for the software fwnode device_remove_software_node() will also put()

it leading to a double free:

[ 82.665598] ------------[ cut here ]------------

[ 82.665609] refcount_t: underflow; use-after-free.

[ 82.665808] WARNING: CPU: 3 PID: 1502 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x11

...

[ 82.666830] RIP: 0010:refcount_warn_saturate+0xba/0x110

...

[ 82.66

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References